Pinpoint Test I: DTC U0238

Information and Entertainment System

Pinpoint Tests

Pinpoint Test I: DTC U0238

Normal Operation

The Audio Control Module (ACM) receives several audio system messages from the Speech Recognition Module (SRM) via the Medium Speed Controller Area Network (MS-CAN).

- DTC U0238 (Lost Communication With Audio Control Module "D" ( DSP)) - set by the ACM when network messages are missing from the SRM for greater than 10 seconds with the ignition in RUN.

This pinpoint test is intended to diagnose the following:

- Communication network concern
- ACM
- SRM


PINPOINT TEST I: DTC U0238

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I1 CHECK THE ACM DTCs


NOTE: If new modules were installed prior to the DTC being set, the module configuration may have been incorrectly set during Programmable Module Installation (PMI) or the PMI may not have been carried out.

- Ignition ON.
- Clear the ACM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds.
- Carry out the ACM self-test using the scan tool.
- Is DTC U0238 still present?

Yes
GO to I2.

No
The system is operating correctly at this time. The DTC may have been set due to a prior low voltage condition.

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I2 VERIFY THE CUSTOMER CONCERN


- Verify that there is an observable symptom present.
- Is an observable symptom present?

Yes
GO to I3.

No
The system is operating correctly at this time. The DTC may have been set due to an intermittent fault in the network wiring. CHECK the MS-CAN wiring between the SRM and the ACM for an intermittent fault.

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I3 CHECK THE COMMUNICATION NETWORK


- Ignition ON.
- Carry out the network test using the scan tool.
- Does the SRM pass the network test?

Yes
GO to I4.

No
REFER to Module Communications Network Testing and Inspection.

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I4 CHECK THE BATTERY VOLTAGE


- Measure the battery voltage.
- Is the battery voltage between 10 and 15 volts?

Yes
INSTALL a new SRM. REFER to Speech Recognition Module (SRM) Service and Repair. CLEAR the ACM DTCs. REPEAT the self-test. If DTC U0238 is still present, INSTALL a new ACM. REFER to Audio Control Module (ACM) Audio Control Module (ACM). TEST the system for normal operation.

No
REFER to Charging System Testing and Inspection to diagnose the charging system.

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